In the field of optical networks, various optical devices have recently been developed such as an OADM (Optical Add-Drop Multiplexer) whereby desired wavelengths of optical signals can be added and dropped, and a WXC (Wavelength Cross-Connect) whereby desired wavelengths of optical signals can be re-routed. Such optical devices make it possible to construct networks having complex topologies such as ring interconnection and mesh connection, with the result that the scale of optical networks keeps expanding.
Meanwhile, a WDM (Wavelength Division Multiplexing) network whose scale can be easily expanded at low cost has conventionally been developed for an HCN (Hyper-Cube Network) wherein HCN connection is established between a plurality of nodes by using WDM techniques and AWG (Arrayed Waveguide Grating) techniques (see Japanese Laid-open Patent Publication No. 2001-60922, for example).
As a result of the expansion of the scale of optical networks, however, more and more connection limits have come to be encountered in optical hub facilities. A problem has therefore arisen in that optical network design apparatus for designing path routing across optical networks often fail to provide appropriate routing results with respect to optical networks expanded in scale.